#include <iostream>
#include <cmath>
using namespace std;
int main(int argc, char **argv[])
{
  double x1, y1, x2, y2;
  cout << "vvedite koordinati pervoy tochki x1 i y1: ";
  cin >> x1 >> y1;
  cout << "vvedite koordinati vtoroy tochki x2 i y2: ";
  cin >> x2 >> y2;
  cout << "rasstoyanie megdu tochkami:" << sqrt(pow((x2 - x1), 2.0) + pow((y2 - y1), 2.0)) << endl;
  return 0;
}
